Multiple ChoiceThe brakes of your car can provide an acceleration of 4.6m/s2. You're speeding at 37.5 m/s and suddenly see a police car, so you slam the brakes. How long will it take for your car to slow down to the speed limit of 25 m/s?2148views54rank3comments
Multiple ChoiceStarting from rest, a car accelerated to 20m/s in 4s. What was the magnitude of the car's constant acceleration?303views
Multiple ChoiceAn explorer on the moon, where there is no atmosphere, simultaneously drops a hammer, a feather and a steel ball from the same height. Which will hit the ground first?302views
Multiple ChoiceHank the hammerhead shark was swimming in the negative direction with a speed of 2.0m/s. 1.0 second later he was swimming with a velocity of −4m/s. What was his average acceleration during the 1.0 second interval?546views3rank1comments
Textbook QuestionA car sits on an entrance ramp to a freeway, waiting for a break in the traffic. Then the driver accelerates with constant acceleration along the ramp and onto the freeway. The car starts from rest, moves in a straight line, and has a speed of 20 m/s(45 mi/h) when it reaches the end of the 120-m-long ramp. (b) How much time does it take the car to travel the length of the ramp?663views1rank
Textbook QuestionA car sits on an entrance ramp to a freeway, waiting for a break in the traffic. Then the driver accelerates with constant acceleration along the ramp and onto the freeway. The car starts from rest, moves in a straight line, and has a speed of 20 m/s(45 mi/h) when it reaches the end of the 120-m-long ramp. (a) What is the acceleration of the car?1327views
Textbook QuestionA rocket starts from rest and moves upward from the surface of the earth. For the first 10.0 s of its motion, the vertical acceleration of the rocket is given by ay = (2.80 m/s3)t, where the +y-direction is upward. (b) What is the speed of the rocket when it is 325 m above the surface of the earth?412views
Textbook QuestionA rocket starts from rest and moves upward from the surface of the earth. For the first 10.0 s of its motion, the vertical acceleration of the rocket is given by ay = (2.80 m/s3)t, where the +y-direction is upward. (a) What is the height of the rocket above the surface of the earth at t = 10.0 s?1483views1rank
Textbook QuestionA turtle crawls along a straight line, which we will call the x-axis with the positive direction to the right. The equation for the turtle's position as a function of time is x(t) = 50.0 cm + (2.00 cm/s)t − (0.0625 cm/s^2)t^2. (a) Find the turtle's initial velocity, initial position, and initial acceleration.1212views
Textbook QuestionCALC. A car's velocity as a function of time is given by v_x(t) = α + βt^2, where α = 3.00 m/s and β = 0.100 m/s^3. (a) Calculate the average acceleration for the time interval t = 0 to t = 5.00 s.1856views1rank
Textbook QuestionA race car starts from rest and travels east along a straight and level track. For the first 5.0 s of the car's motion, the eastward component of the car's velocity is given by vx(t) = (0.860 m/s^3)t^2. What is the acceleration of the car when vx = 12.0 m/s?2556views2rank
Textbook QuestionA particle's velocity is given by the function 𝓋ₓ = (2.0 m/s) sin (πt), where t is in s. b. What is the particle's acceleration at that time?332views
Textbook QuestionA particle's velocity is described by the function vₓ = (t² ─ 7t + 10) m/s, where t is in s. b. What is the particle's acceleration at each of the turning points?421views
Textbook QuestionA good model for the acceleration of a car trying to reach top speed in the least amount of time is a𝓍 = a₀ ─ kv𝓍, where a₀ is the initial acceleration and k is a constant. b. Find an expression for the car's velocity as a function of time.537views
Textbook QuestionAt this instant, the particle is speeding up and curving upward. What is the direction of its acceleration? 296views
Textbook QuestionA sports car moving at constant velocity travels 120 m in 5.0 s. If it then brakes and comes to a stop in 3.7 s, what is the magnitude of its acceleration (assumed constant) in m/s², and in g's (g = 9.80 m/s²) ?359views
Textbook QuestionThe position of an object is given by 𝓍 = At + Bt², where 𝓍 is in meters and t is in seconds. (b) What is the acceleration as a function of time?"269views
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