Answer:
Explanation:
Speed of car =22.5miles/hr
U=22.5miles/hour
Applied brake and come to rest
Final velocity, =0
t, =2sec
Given that,
Speed=distance /time
Then,
Distance, =speed, ×time
Converting mile/hour to m/s
Given that
Use: 1 mile= 1600 m, 1 h= 3600s
22.5miles/hour × 1600m/mile × 1hour/3600s
Therefore, 22.5mile/hour=10m/s
Using speed =10m/s
Distance =speed ×time
Distance=10×2
Distance, =20m
The distance travelled before coming to rest is 20m.
Answer:
(177.94 ± 3.81) cm^2
Explanation:
l + Δl = 21.7 ± 0.2 cm
b + Δb = 8.2 ± 0.1 cm
Area, A = l x b = 21.7 x 8.2 = 177.94 cm^2
Now use error propagation



So, the area with the error limits is written as
A + ΔA = (177.94 ± 3.81) cm^2
Answer:
600m
Explanation:
30×20 at a constant speed is 600m.
The kinetic energy of a moving object is given by

where m is the object's mass and v its velocity.
In our problem, the initial kinetic energy is:

while the final kinetic energy is:

So, the kinetic energy lost by Lucy and her bike is