F = 2820.1 N
Explanation:
Let the (+)x-axis be up along the slope. The component of the weight of the crate along the slope is -mgsin15° (pointing down the slope). The force that keeps the crate from sliding is F. Therefore, we can write Newton's 2nd law along the x-axis as
Fnet = ma = 0 (a = 0 no sliding)
= F - mgsin15°
= 0
or
F = mgsin15°
= (120 kg)(9.8 m/s^2)sin15°
= 2820.1 N
Answer:
2.49 seconds
Explanation:
From the question,
a = (v-u)/t............................ Equation 1
Where a = acceleration, v = final velocity, u = initial velocity, t = time
Make t the subject of the equation
t = (v-u)/a.......................... Equation 2
Given: v = 6.5 m/s, u = 11 m/s, a = -1.81 m/s²
Substitute these values into equation 2
t = (6.5-11)/(-1.81)
t = -4.5/-1.81
t = 2.49 s
The wave phenomenon known as "destructive interference".
