Answer:
1. It won't break
2. 0.5 squared meters
Explanation:
1. Pressure (P) is force (F) exerted over an area(A). Greater the force or smaller the area, the pressure will be greater. This is presented by an equation:
P = F / A
This metallic object can be placed on the table in 3 different positions, depending on which its side is pressed against the table. Since its dimensions are 3 • 6 • 8 m, surface areas of these sides are:
A1 = 3 • 6 = 18m^2
A2 = 3 • 8 = 24m^2
A3 = 6 • 8 = 48m^2
It is already stated that the smaller are, greater the pressure, so this object will exert the greatest pressure if it's placed on the table with its 18m^2 side. In this case, pressure will be:
P = 400N / 18m^2
P = 22.2 N/m^2 (N/m^2 is the same unit as Pascal)
So, the table can withstand 250 Pa of pressure, the object exerts only 22.2 Pa, which means that the glass table won't break.
2. Again, we need to know the equation that connects the force and the pressure, and that is:
P = F / A
In this case, we have both the force and the pressure, and we want to find the surface of the area. From the previous equation, area can be found as:
A = F / P
A = 20N / 40Pa (N/m^2)
A = 0.5 m^2
So, the answer is: this pressure is exerted on the area of half of squared metar.
conservation of momentum ... that before = that after ... change zero
Weight can be explained as the force with which the gravity pulls an object. Your weight will not be the same in all planets. In moon, you will weigh far lesser than how much you weigh on the earth. However, in earth and in the moon, your mass will remain the same.
Answer:
Explanation:
Given
Velocity = 388m/s
Height S = 2.89m
Required
Time
Using the equation of motion
S =ut+1/2gt²
2.89 = 388t+1/2(9.8)t²
2.89 = 388t+4.9t²
Rearrange
4.9t²+388t-2.89 =0
Factorize
t = -388±√388²-4(4.9)(2.89)/2(4.9)
t= -388±√(388²-56.644)/9.8
t = -388±387.93/9.8
t =0.073/9.8
t = 0.00744 seconds
Answer:
3.0 seconds
Explanation:
The time of flight of a projectile (the time it takes to reach the ground) does not depend on the horizontal motion, but only on its vertical motion.
In fact, the time of flight is determined by the suvat equation:
where
s is the vertical displacement
u is the initial vertical velocity (0, in case of these two projectiles)
g = 9.8 m/s^2 is the acceleration of gravity (assuming downward as positive direction)
t is the time of flight
Re-arranging the equation, we get
We see that this time depends only on s (the heigth of the cliff) and g: therefore, since the two projectiles are launched from the same height, they take the same time to reach the ground, 3.0 seconds.
