A body starting from rest accelerates at the rate of 20 metres per second squared. What is the distance covered until the body reaches a velocity of 50 metres per second?
- 6.25 metres.
- 25.0 metres.
- 62.5 metres.
Explanation
Starting from rest, use v squared = 2as, so distance s = v squared / (2a) = 50 squared / (2 x 20) = 2500 / 40 = 62.5 m. This is the displacement needed to reach 50 m/s at the stated acceleration.
gav_18s asking:
which equation for this?
Community Comments (4)
S
sta8ispolemi Posts: 9 22.10.2014 / 21:29
velocity= distance/time
acceleration= velocity/time
acceleration= velocity/time
N
nkris10 Posts: 2 07.03.2017 / 13:45
what was used for time?
J
JD2016 Posts: 54 08.03.2017 / 22:57
v**2 = u**2 + 2as
v= final velocity = 20m/s
u= initial velocity = 0 (starting from rest).
a = acceleration = 20m/s**2
S= distance travelled.
You have everything except s. Fill in the equation and you get s = 62.5 m as the answer.
v= final velocity = 20m/s
u= initial velocity = 0 (starting from rest).
a = acceleration = 20m/s**2
S= distance travelled.
You have everything except s. Fill in the equation and you get s = 62.5 m as the answer.
E
Edga5251 Posts: 2 11.11.2018 / 15:51
v**2 = u**2 + 2as
v= final velocity = 50m/s
u= initial velocity = 0 (starting from rest).
a = acceleration = 20m/s**2
S= distance travelled.
You have everything except s. Fill in the equation and you get s = 62.5 m as the answer.
v**2 = u**2 + 2as (2500=0+20*S); 2500=20S, S=62.5
v= final velocity = 50m/s
u= initial velocity = 0 (starting from rest).
a = acceleration = 20m/s**2
S= distance travelled.
You have everything except s. Fill in the equation and you get s = 62.5 m as the answer.
v**2 = u**2 + 2as (2500=0+20*S); 2500=20S, S=62.5
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