#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:
The true weight of the aluminium is
4.5021 kg
Explanation:
Given data
= 4.5 kg
= 1.29 
= 2.7× 
The true mass of the aluminium is given by

Put all the values in above equation we get

4.5021 kg
Therefore the true weight of the aluminium is
4.5021 kg
according to the second law of dynamics F = m • a => a = F / m
Ans: Time <span>taken by a pulse to travel from one support to the other
= 0.348s</span>
Explanation:First you need to find out the speed of the wave.
Since
Speed = v =

Where
T = Tension in the cord = 150N
μ = Mass per unit length = mass/Length = 0.65/28 = 0.0232 kg/m
So
v =

= 80.41 m/s
Now the time-taken by the wave = t = Length/speed = 28/80.41=
0.348s