Explanation:
Let h is the height of the plane above ground. x is the horizontal distance between the ground and the airport. Let s(t) is the distance between the plane and the airport. So,
...........(1)
Given, h = 4, x = 40 and s(t) = -20 mph
Differentiate equation (1) wrt t


When x = 40, 



So, the speed of the airplane is 241.14 m/s. Hence, this is the required solution.
Formula for potential energy is V=mgh, where m is mass in KG, g is earth acceleration (10 m/s^2), and h its height in meters. We know mass, acceleration is constant and also known, we know height also. Lets substitute
V=75*10*300=225000[J]=225[kJ] - its the answer
Answer:
mass is lifted 1.8 m. What is the potential energy of the mass 4. A 100 kg
Answer:
option A
Explanation:
given,
For exerted by the worker = 245 N
angle made with horizontal = 55°
we need to calculate Force which is not used to move the crate = ?
Movement of crate is due to the horizontal component of the force.
Crate will not move due to vertical force acting on the it.



hence, worker's force not used to move the crate is equal to 200.69
The correct answer is option A
Answer:
Time taken to reach the tree
they have given the maximum height which is 25m
therefore...
v=u+at (upward)
0 = 45sin(20)-9.81t
t = 1.56s