Answer:
here given is a weight
then force becomes mg
that is F=Mg
=4*9.8
then by using the formula
F=Ma
a=F/M
=4*9.8/9.8
=4
Explanation:
Answer: 
beta particles
Explanation:
Given mass = 14.0 g
Molar mass = 137 g/mol
According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass and contains avogadro's number 
of particles.
1 mole of cesium contains atoms =
0.102 moles of cesium contains atoms = 
The relation of atoms with time for radioactivbe decay is:
Where 
=atoms left undecayed
= initial atoms
t = time taken for decay = 3 minutes
= half life = 30.0 years = 
minutes
The fraction that decays : 
Amount of particles that decay is = 
Thus beta particles are emitted by a 14.0-g sample of cesium-137 in three minutes.
Answer:
k = 17043.5 N/m = 17.04 KN/m
Explanation:
First we need to find the force applied by safe pn the spring:
F = Weight of Safe
F = mg
where,
F = Force Applied by the safe on the spring = ?
m = mass of safe = 800 kg
g = 9.8 m/s²
Therefore,
F = (800 kg)(9.8 m/s²)
F = 7840 N
Now, using Hooke's Law:
F = kΔx
where,
K = Spring Constant = ?
Δx = compression = 46 cm = 0.46 m
Therefore,
7840 N = k (0.46 m)
k = 7840 N/0.46 m
<u>k = 17043.5 N/m = 17.04 KN/m</u>
Acceleration = (Vf - Vi)/t
Since Vf= 60m/s
Vi= 15m/s
T= 15s
=> a= (60m/s - 15m/s)/15s
= 3
So the acceleration is 3m/s^2
The correct answer is B. it converts mechanical energy to electrical energy.
