I think this is the answer hope it helps
Answer:
The electric field strength is 
Explanation:
Given that,
Magnetic field = 0.150 T
Speed 
We need to calculate the electric field strength
Using formula of velocity


Where, v = speed
B = magnetic field
Put the value into the formula



Hence, The electric field strength is 
Answer:
Speed changes at the rate of 24 m/s for each second over time.
Explanation:
We are told the object's acceleration is equal to 24 m/s²
Now we know that acceleration can also be defined as the rate of change of speed with time. Also speed has a unit known as m/s.
Thus, we can rephrase the acceleration in this question to mean;
Speed changes at the rate of 24 m/s for every second with time.
××

×
50N is your force and the acceleration is -9.8m/s^2 due to gravity.
So, you just plug that in.

BUT you know that mass cannot be negative, so you just disregard the negative sign and the mass of the rock is 5.102 grams.
Answer:
16.33°C
Explanation:
Applying,
Heat lost by copper = heat gained by water
cm(t₁-t₃) = c'm'(t₃-t₂).............. Equation 1
Where c = specific heat capacity of copper, m = mass of copper, c' = specific heat capacity of water, m' = mass of water, t₁ = initial temperature of copper, t₂ = initial temperature of water, t₃ = final equilibrium temperature.
From the question,
Given: m = 50 kg, t₁ = 140°C, m' = 90 L = 90 kg, t₂ = 10°C
Constant: c = 385 J/kg°C, c' = 4200J/kg°C
Substitute these values into equation 1
50(385)(140-t₃) = 90(4200)(t₃-10)
(140-t₃) = 378000(t₃-10)/19250
(140-t₃) = 19.64(t₃-10)
140-t₃ = 19.64t₃-196.6
19.64t₃+t₃ = 196.4+140
20.64t₃ = 336,4
t₃ = 336.4/20.6
t₃ = 16.33°C