Explanation:
(10) Mass of a soccer player, m = 0.42 kg
Initial speed, u = 0
Final speed, v = 32.5 m/s
Time, t = 0.21 s
We need to find the force that sends soccer ball towards the goal.
Force, F = ma
So, 65 N of force soccer ball sends towards the goal.
(11) Mass of the satellite, m = 72,000 kg
Initial speed, u = 0 m/s
Final speed, v = 0.63 m/s
Time, t = 1296 s
We need to find the force is exerted by the rocket on the satellite.
Force, F = ma
So, 35 N of the force is exerted by the rocket on the satellite.
Hence, this is the required solution.
Answer:
67
Explanation:
- The atomic number (Z) of an atom is equal to the number of protons in the nucleus
- The mass number (A) of an atom is equal to the sum of protons and neutrons in the nucleus
Therefore, calling p the number of protons and n the number of neutrons, for element X we have:
Z = p = 23
A = p + n = 90
Substituting p=23 into the second equation, we find the number of neutrons:
n = 90 - p = 90 - 23 = 67
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Answer:
Vi = 8.28 m/s
Explanation:
This problem is related to the projectile motion.
As we know there are two components of motion associated with this, the horizontal component and vertical component.
The horizontal distance covered by the ball is
Vx*t = x
Vx*t = 5.3
Vx = 5.3/t eq. 1
Also we know that
Vx = Vicos(60)
Vx = Vi*0.5 eq. 2
equate eq. 1 and eq. 2
5.3/t = Vi*0.5
5.3/0.5 = Vi*t
Vi*t = 10.6 eq. 3
The vertical distance is
Vy = y1 + Vyi*t - 0.5gt²
also we know that
Vyi = Visin(60)
Vyi = Vi*0.866
It is given that V1 = 1.9 m and and Vy = 3 m is the vertical distance
3 = 1.9 + Vi*0.866*t - 0.5gt²
3 = 1.9 + Vi*0.866*t - 0.5(9.8)t²
3 = 1.9 + 0.866(Vi*t) - 0.5(9.8)t²
3 = 1.9 + 0.866(Vi*t) - 0.5(9.8)t²
1.1 = 0.866(Vi*t) - 4.9t²
0.866(Vi*t) = 4.9t² + 1.1
substitute Vi*t = 10.6 in above equation
0.866(10.6) = 4.9t² + 1.1
9.18 = 4.9t² + 1.1
4.9t² = 8.08
t² = 8.08/4.9
t² = 1.648
t = 1.28 sec
Finally, initial speed can be found by substituting the value of t into eq. 3
Vi*t = 10.6
Vi = 10.6/t
Vi = 10.6/1.28
Vi = 8.28 m/s
Answer:
a) The velocity is 2.94m/s
b) 0.441
Explanation:
a) Assume gravity is 9.8m/s^2
Use the equation below to solve for the velocity at 0.30 seconds
,
vf =unknown velocity vi= initial velocity vi=0m/s a= 9.8m/s^2 t=0.30seconds
Step 1: Substitute the variables with the knowns
Step 2: Solve
b)
Use the equation below to solve for the displacement at 0.30 seconds
Step 1: Substitute the same variables with the knowns
Note that vi*t=0 as vi=0m/s
Step 2: Solve
x=0.441m
