The answer is C) Sodium.
~Deceptiøn
Answer:
The final velocity of the car is 36 m/s.
Explanation:
Given;
initial velocity of the car, u = 20 m/s
time of the car acceleration, t = 4 s
acceleration of the car, a = 4 m/s²
the final velocity of the car is calculated as;
v = u + at
where;
v is the final velocity of the car
v = 20 + (4 x 4)
v = 36 m/s
Therefore, the final velocity of the car is 36 m/s.
Answer:
Work done, W = 6153.31 Joules
Explanation:
It is given that,
Weight of piano, W = F = 7382 N
It is pushed 2.16 meters friction less plank
The angle with horizontal, 
When the piano slide up plank at a slow constant rate. The y component of force is taken into consideration. The net force acting on it is given by :

Work done is given by :



W = 6153.31 Joules
So, the work done in sliding the piano up the plank is 6153.31 Joules. Hence, this is the required solution.