Answer:
d = 175 miles
Explanation:
Train is moving towards East with constant speed of 50 mph
While car is moving at speed of 30 mph
so after t = 3 hours
the distance moved by the train is given as


at the same time the distance moved by the car is given as

now we know that both car and train is moving perpendicular to each other
So the distance between them after t = 3 hours is given as



Answer:
The tension in the cord is 
Explanation:
Given:
M = mass
b = radius
R = spool of radius
The equation is:
(eq. 1)
The sum of forces in y:
∑Fy = Mg - T = Ma

Replacing in eq. 1

Answer:
1.122 m/s
Explanation:
So usually a river with a speed of 1 meters per second can transport particle that weighs:

If the particle is twice as massive as usual, then its weights would be 1 * 2 = 2kg
This means the river must be flowing at a speed of

Answer:
3 significant figures
Explanation:
here zero is counted as one of the significant figures since it lies next to an integer.
hence the number has 3 sfg
Let both the balls have the same mass equals to m.
Let
and
be the speed of the ball1 and the ball2 respectively, such that

Assuming that both the balls are at the same level with respect to the ground, so let h be the height from the ground.
The total energy of ball1= Kinetic energy of ball1 + Potential energy of ball1. The Kinetic energy of any object moving with speed,
, is 
and the potential energy is due to the change in height is
[where
is the acceleration due to gravity]
So, the total energy of ball1,

and the total energy of ball1,
.
Here, the potential energy for both the balls are the same, but the kinetic energy of the ball1 is higher the ball2 as the ball1 have the higher speed, refer equation (i)
So, 
Now, from equations (ii) and (iii)
The total energy of ball1 hi higher than the total energy of ball2.