Answer:
t = 1.31 s
Explanation:
Given that,
The top of a roof is located 8.52 meters above the ground.
We need to find the time required for the shingles to reach the ground. Let the time be t. Its initial velocity was 0 as it was at rest initially. Using the equation of motion to find it as follows :
Where
t is the time and u = 0
So, it will take 1.31 seconds for the shingles to reach the ground.
#82
here we know that
acceleration = 2 m/s/s
time = 5 s
initial speed = 4 m/s
now we can use kinematics to find the final speed
So correct answer will be option D)
#83
here we know that
acceleration = 3 m/s/s
time = 4 s
initial speed = 5 m/s
now we can use kinematics to find the final speed
So correct answer will be option C)
#84
here we know that
acceleration = 7 m/s/s
time = 3 s
initial speed = 8 m/s
now we can use kinematics to find the final speed
So correct answer will be option C)
Answer:
2.8 N
Explanation:
Fp = 7.7 N
mA = 12.1 kg
mB = 7 kg
Let a be the acceleration and Fc be the contact force between A and B.
By the free body diagram, use Newton's second law
Fp - Fc = mA x a ..... (1)
Fc = mB x a ..... (2)
Adding both the equations
Fp = (mA + mB) x a
7.7 = (12.1 + 7) x a
a = 0.4 m/s^2
Substitute this value in equation (2), we get
Fc = 7 x 0.4 = 2.8 N
Thus, the contact force between the two blocks is 2.8 N.
Explanation:
