Explanation:
u=54 km/h
54*5/18=15 m/s
v=0m/s
t=?
acceleration=-0.5m/s^2
we know that a=v-u/t
so,
t=v-u/a
t=15-0/0.5
=15/0.5
=30
therefore, the time is 30 second
Hope this answer helps you..
Answer:
The value of d is 20.4 m.
(C) is correct option.
Explanation:
Given that,
Initial velocity = 20 m/s
Final velocity = 0
We need to calculate the time
Using equation of motion

Where, u = Initial velocity
v = Final velocity
Put the value into the formula


We need to calculate the distance
Using equation of motion



Hence, The value of d is 20.4 m.
Answer:
human potential energy
Explanation:
It is given that, before a ball rolls down a hill, it has gravitational potential energy.
Before a rubber ball bounces away from a surface, it has elastic potential energy.
Human potential energy allows us to throw a ball. While throwing a ball, we have to apply some force by our muscles in order to done some work.Also, we know that the capacity to do work is called energy.
Hence, the correct option is (D) " human potential energy ".