Answer:
(a) 
(b) 
(c) 
Explanation:
(a) According to Newton's second law, the acceleration of a body is directly proportional to the force exerted on it and inversely proportional to it's mass.
(b) According to Newton's third law, the force that the sled exerts on the girl is equal in magnitude but opposite in the direction of the force that the girl exerts on the sled:
(c) Using the kinematics equation:
For the girl, we have 
and 
. So:
For the sled, we have . So:
When they meet, the final positions are the same. So, equaling (1) and (2) and solving for t:
Now, we solve (1) for 
Answer:
a = 1.16 m/s²
Explanation:
In order to find the acceleration of the ball we will use 3rd equation of motion.
2as = Vf² - Vi²
where,
a = acceleration = ?
s = displacement = 21.9 m
Vf = Final Velocity = 7.14 m/s
Vi = Initial Velocity = 0 m/s (Since, ball starts from rest)
Therefore, using the values, we get:
2a(21.9 m) = (7.14 m/s)² - (0 m/s)²
a = (50.97 m²/s²)/(43.8 m)
<u>a = 1.16 m/s²</u>
Answer:
5.95 A
Explanation:
From the question
R = ρL/A..................... Equation 1
Where R = resistance of the tungsten wire, ρ = Resistivity of the tungsten wire, L = length, A = cross sectional area.
Given: L = 1.5 m, A = 0.8 mm² = 0.8×10⁻⁶ m, ρ = 5.60×10⁻⁸ Ω.m
Substitute these values into equation 1
R = 1.5(5.60×10⁻⁸)/0.8×10⁻⁶
R = 0.084 Ω.
Finally, using Ohm law,
V = IR
Where V = Voltage, I = current
Make I the subject of the equation
I = V/R............... Equation 2
I = 0.5/0.084
I = 5.95 A
