Answer:
14.3kg
Explanation:
Given parameters:
Quantity of heat = 149000J
Change in temperature = 5.23°C
specific heat of the ice = 2000J/kg°C
Unknown:
Mass of the ice in the bag = ?
Solution:
The heat capacity of a substance is given as:
H = m c Ф
H is the heat capacity
m is the mass
c is the specific heat
Ф is the temperature change;
since m is the unknown, we make it the subject of the expression;
m = H/ mФ
m = = 14.3kg
Answer:
Speed of the ball relative to the boys: 25 km/h
Speed of the ball relative to a stationary observer: 35 km/h
Explanation:
The RV is travelling at a velocity of
Here we have taken the direction of motion of the RV as positive direction.
The boy sitting near the driver throws the ball back with speed of 25 km/h, so the velocity of the ball in the reference frame of the RV is
with negative sign since it is travelling in the opposite direction relative to the RV. Therefore, this is the velocity measured by every observer in the reference frame of the RV: so the speed measured by the boys is
v = 25 km/h
Instead, a stationary observer outside the RV measures a velocity of the ball given by the algebraic sum of the two velocities:
v = +60 km/h + (-25 km/h) = +35 km/h
So, he/she measures a speed of 35 km/h.
Answer:
660 centimeters
Explanation:
There are 100 cm in 1 m. To convert from m to cm, multiply by 100.
There are 660 cm in 1 m.
Answer:
R = 4.77 ohms
Explanation:
Four resistors are given such that,
R₁ = 2 ohms
R₂ = 3 ohms
R₃ = 5 ohms
R₄ = 10 ohms
Here, R₁ and R₂ in series. The equivalent is given by :
R₁₂ = R₁ + R₂
= 2 + 5
R₁₂ = 7 ohms
Similarly, R₃ and R₄ are in series. so,
R₃₄ = R₃ + R₄
= 10+5
R₃₄ = 15 ohms
Now, R₁₂ and R₃₄ are in parallel. So,
So, the equivalent resistance s 4.77 ohms.