Answer:

Explanation:
To solve this problem we use the formula for accelerated motion:

We will take the initial position as our reference (
) and the downward direction as positive. Since the rock departs from rest we have:

Which means our acceleration would be:

Using our values:

Answer:
The velocity is 
Henrietta is at distance
from the under the window
Explanation:
From the question we are told that
The speed of Henrietta is 
The height of the window from the ground is 
Generally the time taken for the lunch to reach the ground assuming it fell directly under the window is

=>
=>
Generally the time taken for the lunch to reach Henrietta is mathematically represented as

Here
is the time duration that elapsed after Henrietta has passed below the window the value is given as 4 s
Now
=>
Generally the distance covered by Henrietta before catching her lunch is

=> 
=> 
Generally the speed with which Bruce threw her lunch is mathematically represented as


Answer:
Given
acceleration (a) =1.5ms2
Force(F) =2100N
R. t. c mass (m) =?
Form
F=ma(divided by m both sides)
m=F/a
m=2100/105
m=1400kg
mass of car =1400kg
It acquires a positive electric charge.
Answer:
k = 
b = 
t = 
Solution:
As per the question:
Mass of the block, m = 1000 kg
Height, h = 10 m
Equilibrium position, x = 0.2 m
Now,
The velocity when the mass falls from a height of 10 m is given by the third eqn of motion:

where
u = initial velocity = 0
g = 10
Thus

Force on the mass is given by:
F = mg = 
Also, we know that the spring force is given by:
F = - kx
Thus

Now, to find the damping constant b, we know that:
F = - bv

Now,
Time required for the platform to get settled to 1 mm or 0.001 m is given by:
