Answer:
The mass of Laura and the sled combined is 887.5 kg
Explanation:
The total force due to weight of Laura and friction on the sled can be calculated as follows;

= (400 + 310) N
= 710 N
From Newton's second law of motion, "the rate of change of momentum is directly proportional to the applied force.

where;
is mass of Laura and
is mass of sled
Mass of Laura and the sled combined is calculated as follows;

given
V = Δv = 4-0 = 4m/s
t = 5 s

Therefore, the mass of Laura and the sled combined is 887.5 kg
Answer:
More quiclky
Explanation:
In Earth, there is a gravitional force. So that forces pushed you down faster.
Answer:
The longest wavelength of light is 209 nm.
Explanation:
Given that,
Spring constant = 74 N/m
Mass of electron 
Speed of light 
We need to calculate the frequency
Using formula of frequency

Where, k= spring constant
m = mass of the particle
Put the value into the formula


We need to calculate the longest wavelength that the electron can absorb

Where, c = speed of light
f = frequency
Put the value into the formula



Hence, The longest wavelength of light is 209 nm.
Answer:

Explanation:
Since we know that two sphere is oppositely charged so net electric field at the mid point of two balls will be sum of the electric field due to each ball at the mid point
So we know that

here we know that



so we have


Answer:
a) KA = 1.2 J
b) vB = 5.00 m/s
c) W = 6.30 J
Explanation:
m = 0.600 kg
vA = 2.00 m/s
KB = 7.50 J
a) KA = ?
b) vB = ?
c) W = ?
We can apply the folowing equations
K = 0.5*m*v²
and
W = ΔK = KB- KA
then
a) KA = 0.5*m*vA² = 0.5*(0.600 kg)*(2.00 m/s)²
⇒ KA = 1.2 J
b) KB = 0.5*m*vB² ⇒ vB = √(2*KB / m)
⇒ vB = √(2*7.50 J / 0.600 kg)
⇒ vB = 5.00 m/s
c) W = ΔK = KB- KA = (7.50 J) - (1.2 J)
⇒ W = 6.30 J