Ball rolls 6cm in one second. 6cm x 40 sec = 240cm
Answer:
0.64 J/g°C
Explanation:
Using the formula;
Q = m × c × ∆T
Where;
Q = amount of heat
m = mass (g)
c = specific heat capacity
∆T = change in temperature (°C)
In this case:
Q (water) = - Q (metal)
mc∆T (water) = - mc∆T (metal)
According to the information in this question,
For water; m = 100g, c = 4.18J/g°C, ∆T = (25°C - 20°C)
For metal; m = 50g, c =?, ∆T = (25°C - 90°C)
mc∆T (water) = - mc∆T (metal)
100 × 4.18 × (25°C - 20°C) = - {50 × c × (25°C - 90°C)}
100 × 4.18 × 5 = - {50 × c × -65}
2090 = -{-3250c}
2090 = 3250c
c = 2090/3250
c = 0.643
c = 0.64J/g°C
It is often revealed <span>at the resolution of the story, when the reader can see how the story ends.</span>
Answer:
Please refer to the figure.
q1 is a negative charge, and q2 and q3 are positive charges. So, the force exerted by q1 on q3 is attractive, and the force exerted by q2 on q3 is repulsive, which means F13 is directed towards left, and F23 is also directed towards left.


The net force on q3 is the sum of these two forces:

Since both forces are directed towards left, their sign should be negative.