Answer:
Explanation:
We know that the formula for acceleration is given by:
, where v = Final velocity
u= Initial velocity
Given : The driver of a car traveling 110 km/h slams on the brakes so that the car undergoes a constant acceleration.
i.e. u= 110 km/h [∵ 1 km= 100 meters and 1 hour = 3600 seconds]
v= 0 m/s ( At brake , final velocity becomes 0)
t=4.5 seconds
Substitute all the values in the formula , we get
Hence, the average acceleration of the car during braking is .
Answer:
B. 0.16 m
Explanation:
The vertical distance by which the player will miss the target is equal to the vertical distance covered by the dart during its motion.
Since the dart is thrown horizontally, the initial vertical velocity is zero:
While the horizontal velocity is
The horizontal distance covered is
Since the dart moves by uniform motion along the horizontal direction, the time it takes for covering this distance is
along the vertical direction, the motion is a uniformly accelerated motion with constant downward acceleration g=9.8 m/s^2, so the vertical distance covered is given by